The 2SK2101 part number is followed by an extra 01mr suffix in this 175 KB PDF. The name does not explain that suffix, which could be a document code or revision. It is filed as a schematic but is likely a datasheet for this JIS-registered N-channel FET. Use it to look up maximum ratings, on-resistance, gate threshold and pin layout. Check the marking on the board device before relying on the figures or choosing a substitute.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)